Automotive molding structures of the type adapted to support and guide a car window have been known for years. Traditionally, such moldings are extrusions comprising a metal core strip that is rolled or bent into the desired channel or arch shape. The channel or arch shaped extrusion is snugly fit over or around a door, side or roof panel and provides, in some cases, a decorative interface between the car panel and window. An elastomeric, flocked lip or the like is adhered to the strip and bears upon the window to provide a seal and serve as a guide for window reciprocation in those cases in which the extrusion provides interface between the automobile body and a moving window.
One window pane support and/or guide member is disclosed in U.S. Pat. No. 3,067,455 (Reid). In this patent, a core strip is passed through a first extruder where it is provided with an uncured rubber or rubber material. Downstream from the first extruder, a second extruder provides one or more relatively narrow, longitudinally disposed layers or ribs of uncured sponge rubber on the strip. The rubber is then cured by passing through a heater and is then conveyed to a downstream flocking operation. The flocked core strip passes through forming rolls for formation of the finished channel-shaped form. The advancing strip is then cut into the desired lengthwise dimensions.
In U.S. Pat. No 4,865,796 (Tamura et al.) automobile moldings formed at least partially from a synthetic resin are disclosed. The cross-sectional shape of the extrusion is varied along the extrusion length by removing controlled amounts of the synthetic resin from the advancing extrusion. The extrusions are utilized as window moldings, and so-called drip moldings which are commonly positioned along the lengthwise roof sides of the automobile.
In the manufacture of automobile moldings, especially the so-called "belt line" moldings that border the interface between a car door panel and the bottom outside edge of the door windows, it has become aesthetically fashionable to provide a strip of stiff decorative or ornamental plastic material on the outer or inner side of the arch or channel shaped molding in combination with the lustrous or "chrome" look of an exposed portion of the core material. In addition to these aesthetic functions, the inner portion of the molding comprises a flocked elastomeric lip adapted to bear against the window, sealing the door from the elements, and providing a guide for reciprocating movement of the window.
In order to produce flocked moldings, it is necessary to supply an even coating of adhesive along the desired molding surface so that the short flocking fibers will uniformly adhere thereto. These adhesives are generally applied to the molding after the requisite decorative and elastomer polymers had been extruded onto the travelling core or strip during the process. Commonly, these adhesives are applied to the travelling core by being fed to the nip formed between the core and a specially contoured feed roller; the latter having been specifically configured to correspond to the profiled shape of the core.
Irregularities in the feed of adhesive to this interface or in the shape of the feed roller lead to uneven application of desired adhesive thickness and resulting poor flocking uniformity. The irregularities are a leading source of inferior, reject product that must be culled from acceptable production run quantities. Accordingly, there is a need to provide a method for making flocked, automobile molding members in which flocking adhesive coating uniformity is improved, thereby resulting in reduction of unacceptable product quantities made.
The adhesive compositions themselves are generally of the thermosetting type which require application of heat thereto after the flocking operation in order to cure the adhesive and provide firm support for the fibers. Any process in which this heating step could be eliminated is of great desire as it will lead to considerable savings in energy and process completion time.
Additionally, most of the adhesives utilized for flock adherence to substrate are provided in a volatile organic solvent system such as toluene, MEK, MIK, and others. Accordingly, a process in which emission of VOCs from flock adhesives is minimized is of considerable benefit.